Load-compensating load handling machines



May 25, 1965 F. BENNETT, SR 73,185,316

LOAD-COMPENSATING LOAD HANDLING MACHINES Filed Jan. 14, 1963 3 Sheets-Sheet l INVENTOR.

CHARLES F. BENNETT SR.

ATTORNEY M ED May 25, 1965 F. BENNETT, SR

LOAD-COMPENSATING LOAD HANDLING MACHINES 3 Sheets-Sheet 2 Filed Jan. 14, 1965 .lhllllli I ll INVENTOR.

CHARLES E BENNETT SR.

ATTORNEY May 25, 1965 c. F. BENNETT, SR 3,135,316"

LOAD-COMPENSATING LOAD HANDLING MACHINES 3 Sheets-Sheet 3 Filed Jan. 14, 1963 FIG: 6

REMOVABLE PLUG FOR INSERTING BALL BEARINGS INVENTOR CHARLES E BENNETT SR.

ATTORNEY United States Patent 3,185,316 LOAD-COMPENS TING LOAD HANDLHIG MACHINES Charles F. Bennett, Sr., 157 72nd St., Niagara Falls, N.Y. Filed Jan. 14, 1963, Ser. No. 251,416 7 Claims. (Cl. 212-49) This invention relates to load handling machines and is particularly concerned with such machines which are adapted to compensate for loads in excess of normal loads.

Load handling machines such, for example, as cranes, shovels, clamshells, draglines and hoes are customarily provided with a turntable mounted on a carriage or carrier and, rotatable thereon, a superstructure or cab which carries a pivoted boom, a power plant and controls. Ordinarily the boom is movable through a considerable vertical angle to position the boom tip at varying radial distances from the center of rotation of the turntable. When handling heavy loads the machine is customarily prevented from overturning by the use of out'riggers and a counterweight positioned on the end of the superstructure opposite that on which the boom is mounted. However, even with the use of normal counterweights and Outriggers the lifting of very heavy loads requires the boom to be positioned at a very high angle.

It is an object of the present invention to provide load handling machines having means for automatically compensating for heavy loads.

Another object of the invention is to provide means in a load handling machine for automatically shifting the cab or superstructure thereof to compensate for loads heavier than normal.

Another object of the invention is to provide load handling machines or" the character described in which change in the boom radius is minimized.

A further object of the invention is to provide load handling machines of the character described in which novel means for swinging the superstructure is provided.

Other objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings.

While it will be understood that the present invention is applicable to shovels, hoes, draglines, and similar machines, it is particularly of use with cranes such as are used to lift structural steel and other heavy loads. In the following description, therefore, the invention will be described as applied to such a crane and the drawings are directed to such an embodiment.

In the drawings:

FIGURE 1 is a side view of the superstructure and the turntable of a crane embodying the present invention, the cab being shown in normal forward position with the boom and cables removed.

FIGURE 2 is a view similar to FIGURE 1 with the cab shown in retracted, rear position;

FIGURE 3 is a detail elevation view of a modified form of cab track;

FIGURE 4 is an enlarged detail View in section and elevation of a detent or look for the cab;

FIGURE 5 is a front elevation of the superstructure shown in FIGURE 1;

FIGURE 6 is a top view of the superstructure shown in FIGURE 1;

FIGURE 7 is a top view of the cab in retracted, rear position as shown in FIGURE 2;

FIGURE 8 is an enlarged detail view, partly in section, showing the mounting of the superstructure for rotation and the ring gear pinion mounting; and

FIGURE 9 is a side view of a crane incorporating the present invention which illustrates the way in which change in the boom radius is minimized when the cab shifts to compensate for heavy loads.

Referring to FIGURE 1, the numeral ltl indicates the mobile base or carrier for the crane. The crane usually is mounted on a truck or other self-propelled vehicle chassis. Secured to the base 10 by suitable means such as bolts 11 is a bevelled ring gear 12 which constitutes a portion of a turntable. The superstructure which rotates thereon comprises a cab 14 which includes a carriage for supporting the boom 32 (see FIGURE 9). The cab, which contains a position for the operator, the power plant and controls (not shown), the cable drums 16 and cables 17 (see FIGURE 5), and the swing mechanism 18 is supported on front rollers 21 and rear rollers 22.

The wheels or rollers 21 and 22 are carried by the inwardly extending lower arms of the G-shaped brackets 23 and are held thereby in rolling engagement in the parallel U-shaped tracks 25 and 26 which extend longitudinally of the turntable on opposite sides thereof and form a portion of the rotatable structure. The tracks 25 and 2 6 are suitably secured, as, for example, by welding, to the outer faces of the longitudinal I-beams 27 and 28, respectively, and are braced therein by filler bars 29 which also may be welded in place on the beams 27 and 28. The I-bearns constitute a part of the turntable for the cab 14- which will be described in detail hereinafter.

The cab 14 has, at the forward end of its carriage, spaced boom foot brackets 31 to which, as shown in FIGURE 9, the boom 32 is attached at its lower end by suitable pins (not shown). These pins pass through the holes 33 in the brackets 31 and mount the boom for pivotal movement in a vertical plane. Also, as shown in FIGURE 9, a mast 34 may be pivotally mounted by pins (not shown) which pass through the other holes 35 in the brackets 31.

As will be seen from FIGURES 1 and 2, the tracks 25 and 26 in which the rollers 21 and 22 travel are preferably shaped as wide spread Vs, i.e. each track comprises two generally horizontal sections of substantially equal length which are, however, inclined upwardly from their juncture at slight angles. An angle of about 4 from the horizontal is preferred for each section of the tracks, but angles from about 2 to about 5 may be used satisfactorily. It is preferred for the angles of the track sections to be substantially equal, but this is not in all cases essential.

The tracks 25 and 26 may be formed in any suitable way. For example, two straight sections may be arranged end to end at the desired angles and welded together. It is also possible, as shown in FIGURE 3, to use a gradually curved track. The track 36 in FIGURE 3 is for func tional purposes the equivalent of the track 25 since the ends of the track are slightly elevated above the center portion.

In the normal position of the cab 14, as shown in FIGURE 1, the front supporting rollers 21 are positioned adjacent the front ends of the tracks 25 and 26 while the back or rear rollers 22 are positioned just slightly rearwardly of the junctures of the track sections on each side of the carriage. It will be seen, therefore, that downward force exerted adjacent the front end of the cab, as by a load applied through the boom '32 on the brackets 31, will tend to cause the cab to move rearwardly along the tracks 25 and 26. If the load is sufficiently heavy the front of the cab assumes a position, as in FIGURE 2, over the lowest points of the tracks, i.e. at substantially the midpoints thereof.

Normally, the weight of the cab and its contents and the counterweight (not shown), which is conventionally provided at the rear of the cab, maintain the cab 14 in its normal forward position as shown in FIGURE 1. However, when a load greater than normal is picked up, the excess force applied adjacent the front of the cab through the boom causes the cab to move rearwardly, thus shifting the weight of the cab and counterweight Patented May 25, 1965 .the superstructure rotates.

released the cab will return-to its normal, forward position under the influence of the counterweight.

Detents 38 and 39 may be used to hold the cab 14 in any desired position on the tracks and 26 or to limit movement thereof. Each'of the detents comprises a roller engaging portion 40 and is provided with clamping means 41 by which it maybe secured to a flange of one of the tracks. Any desired number of detents may be employed.

Although, as indicated above, the principle of the present invention is adapted for use with load handling equipment of all types, it is also particularly useful in the common types of load handling machines in which cut from FIGURE 8.

As shown in FIGURE 8, a ring 44- is provided within the ring gear 12 and is rotatably secured to the latter by a ball assembly 45 mounted between the ring gear 12 and the ring 44 in matching grooves formed therein. Thus, the ring 44 is held in place within the ring gear but can rotate freely. A filler hole is provided in the ring 44- for placing and removing the balls and for introducing lubricant, the hole being normally closed as by a screw plug 46.

Suitably secured, for example, by welding, to the inner face of the ring 44 are a plurality of spaced vertically extending supporting posts 48. These posts are attached, as by welding, at their upper ends to the cross members 49 to which the l-beams 27 and 28 are suitably secured on opposite sides of the turntable. Thus the whole superstructure, including the cab 14 and the boom carriage, may revolve freely, in a horizontal plane, with respect to the .mobile base 10.

Similar turntables are, of course, used on conventional load handling equipment. Because, however, the cab of the novel apparatus herein disclosed moves radially with respect to the turntable, the rotating means used with conventional apparatus cannot be employed. The invention, therefore, comprehends the provision of novel rotating means for the superstructure. This includes a transverse bar or plate 50 extending between and secured to the beams 27 and 28 at the forward ends thereof. Supported from the plate 50 at its center point is a bearing block 51 in which is seated the end of a pinion shaft 52.

Carried on the shaft 52 which is non-round and preferably square in cross section, is a pinion 53 which engages the teeth of the ring gear 12. Rotation of the shaft 52, therefore, will cause rotation of the superstructure with respect to the base. At its other end the shaft 52 is slidably received in a hollow drive shaft 55. The cross section of the interior of the shaft 55 is the same as that of the shaft 52 whereby rotation of the former will cause rotation of the latter. The drive shaft 55 is operably con- To permit such rotation a turntable is provided, details'of which will be more apparnected for rotation by the schematically shown swing mechanism which is designated by the numeral 18. Such mechanism may be conventional or of any desired construction.

It will be evident that the present invention provides a novel and highly useful construction for load handling machines whereby the machine is self-compensating for heavy loads and is therefore convenient for use under varying conditions. While a specific embodiment'of the invention has been shown and described for illustrative purposes, it will be understood that many variations and modifications can be made, either in constructing a new machine or in reconstructing a conventional machine, Without departing from the spirit of the invention.

1 claim:

1. A self-counterbalancing, load-handling machine which comprises a mobile base and a superstructure mounted thereon; said superstructure comprising a boom supporting carriage, a boom pivotally mounted on said carriage for swinging movement in a vertical plane, and supportim means for said carriage, said supporting means comprising parallel tracks carried by said superstructure,

said tracks being parallel with the plane in which said boom swings, each track including portions that are angularly disposed in a vertical plane and the ends of each track being higher than the center portion thereof, and

means carried by said carriage in rolling engagement with said tracks, whereby said carriage is movable along said tracks by changes in load on said boom.

2. A load-handling machine as set forth in claim 1 in which said superstructure is rotatable horizontally on said base.

3. A load-handling machine as set forth in claim 2 in which said tracks are rotatable horizontally with said superstructure.

4. A load-handling machine as set forth in claim 3 in which said carriage includes wheels in rolling engagement with said tracks.

5. A load-handling machine -as set forth in claim 4 in which said tracks comprise means for holding said wheels in engagement with said tracks.

6. A load-handling machine as set forth in claim 1 which comprises means for selectively locking said carriage against movement on said tracks.

7. A load-handling machine as set forth in claim 5 which comprises means for selectively locking said carriage against movement'on said tracks.

References Cited by the Examiner UNITED STATES PATENTS 2,292,870 8/42 Dixon 2121l X- 2,526,613 10/50 Tanguy 21249 2,602,552 7/52 Orloff 212-59 2,925,922. 2/60 Frenzel 212-35 FOREIGN PATENTS 267,849 12/ 13 Germany.

SAMUEL'F. COLEMAN, Primary Examiner. 

1. A SELF-COUNTERBALANCING, LOAD-HANDLING MACHINE WHICH COMPRISES A MOBILE BASE AND A SUPERSTRUCTURE MOUNTED THEREON; SAID SUPERSTRUCTURE COMPRISING A BOOM SUPPORTING CARRIAGE, A BOOM PIVOTALLY MOUNTED ON SAID CARRIAGE FOR SWINGING MOVEMENT IN A VERTICAL PLANE, AND SUPPORTING MEANS FOR SAID CARRIAGE, SAID SUPPORTING MEANS COMPRISING PARALLEL TRACKS CARRIED BY SAID SUPERSTRUCTURE, SAID TRACKS BEING PARALLEL WITH THE PLANE IN WHICH SAID BOOM SWINGS, EACH TRACK INCLUDING PORTIONS THAT ARE ANGULARLY DISPOSED IN A VERTICAL PLANE AND THE ENDS OF EACH TRACK BEING HIGHER THAN THE CENTER PORTION THEREOF, AND MEANS CARRIED BY SAID CARRIAGE IN ROLLING ENGAGEMENT WITH SAID TRACKS, WHEREBY SAID CARRIAGE IS MOVABLE ALONG SAID TRACKS BY CHANGES IN LOAD IN SAID BOOM. 